view mod_limit_auth/mod_limit_auth.lua @ 5648:c217f4edfc4f

misc/mtail: Start of an mtail config Stashing it here in case anyone wants to continue working on it. Currently it's only counting log messages by level. Due to the permissions set by systemd on Prosody logs, mtail never managed to start correctly until permissions were manually relaxed.
author Kim Alvefur <zash@zash.se>
date Sun, 17 Sep 2023 13:36:30 +0200
parents 2a5a44d5b935
children
line wrap: on
line source

-- mod_limit_auth

local st = require"util.stanza";
local new_throttle = require "util.throttle".create;

local period = math.max(module:get_option_number(module.name.."_period", 30), 0);
local max = math.max(module:get_option_number(module.name.."_max", 5), 1);

local tarpit_delay = module:get_option_number(module.name.."_tarpit_delay", nil);
if tarpit_delay then
	local waiter = require "util.async".waiter;
	local delay = tarpit_delay;
	function tarpit_delay()
		local wait, done = waiter();
		module:add_timer(delay, done);
		wait();
	end
else
	function tarpit_delay() end
end

local throttles = module:shared"throttles";

local reply = st.stanza("failure", { xmlns = "urn:ietf:params:xml:ns:xmpp-sasl" }):tag("temporary-auth-failure");

local function get_throttle(ip)
	local throttle = throttles[ip];
	if not throttle then
		throttle = new_throttle(max, period);
		throttles[ip] = throttle;
	end
	return throttle;
end

module:hook("stanza/urn:ietf:params:xml:ns:xmpp-sasl:auth", function (event)
	local origin = event.origin;
	if origin.type ~= "c2s_unauthed" then return end
	if not get_throttle(origin.ip):peek(1) then
		origin.log("warn", "Too many authentication attepmts for ip %s", origin.ip);
		tarpit_delay();
		origin.send(reply);
		return true;
	end
end, 10);

module:hook("authentication-failure", function (event)
	get_throttle(event.session.ip):poll(1);
end);

module:add_timer(14400, function (now)
	local old = now - 86400;
	for ip, throttle in pairs(throttles) do
		if throttle.t < old then
			throttles[ip] = nil;
		end
	end
end);